/*
 * Agent.h
 * RVO2 Library
 *
 * Copyright 2008 University of North Carolina at Chapel Hill
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Please send all bug reports to <geom@cs.unc.edu>.
 *
 * The authors may be contacted via:
 *
 * Jur van den Berg, Stephen J. Guy, Jamie Snape, Ming C. Lin, Dinesh Manocha
 * Dept. of Computer Science
 * 201 S. Columbia St.
 * Frederick P. Brooks, Jr. Computer Science Bldg.
 * Chapel Hill, N.C. 27599-3175
 * United States of America
 *
 * <http://gamma.cs.unc.edu/RVO2/>
 */

#ifndef RVO_AGENT_H_
#define RVO_AGENT_H_

/**
 * \file       Agent.h
 * \brief      Contains the Agent class.
 */

#include "Definitions.h"
#include "RVOSimulator.h"

namespace RVO {
    /**
     * \brief      Defines an agent in the simulation.
     */
    class Agent {
    private:
        /**
         * \brief      Constructs an agent instance.
         * \param      sim             The simulator instance.
         */
        explicit Agent(RVOSimulator *sim);

        /**
         * \brief      Computes the neighbors of this agent.
         */
        void computeNeighbors();

        /**
         * \brief      Computes the new velocity of this agent.
         */
        void computeNewVelocity();

        /**
         * \brief      Inserts an agent neighbor into the set of neighbors of
         *             this agent.
         * \param      agent           A pointer to the agent to be inserted.
         * \param      rangeSq         The squared range around this agent.
         */
        void insertAgentNeighbor(const Agent *agent, double &rangeSq);

        /**
         * \brief      Inserts a static obstacle neighbor into the set of neighbors
         *             of this agent.
         * \param      obstacle        The number of the static obstacle to be
         *                             inserted.
         * \param      rangeSq         The squared range around this agent.
         */
        void insertObstacleNeighbor(const Obstacle *obstacle, double rangeSq);

        /**
         * \brief      Updates the two-dimensional position and two-dimensional
         *             velocity of this agent.
         */
        void update();

        std::vector<std::pair<double, const Agent *> > agentNeighbors_;
        size_t maxNeighbors_;
        double maxSpeed_;
        double neighborDist_;
        Vector2 newVelocity_;
        std::vector<std::pair<double, const Obstacle *> > obstacleNeighbors_;
        std::vector<Line> orcaLines_;
        Vector2 position_;
        Vector2 prefVelocity_;
        double radius_;
        RVOSimulator *sim_;
        double timeHorizon_;
        double timeHorizonObst_;
        Vector2 velocity_;

        size_t id_;

        friend class KdTree;
        friend class RVOSimulator;
    };

    /**
     * \relates    Agent
     * \brief      Solves a one-dimensional linear program on a specified line
     *             subject to linear constraints defined by lines and a circular
     *             constraint.
     * \param      lines         Lines defining the linear constraints.
     * \param      lineNo        The specified line constraint.
     * \param      radius        The radius of the circular constraint.
     * \param      optVelocity   The optimization velocity.
     * \param      directionOpt  True if the direction should be optimized.
     * \param      result        A reference to the result of the linear program.
     * \return     True if successful.
     */
    bool linearProgram1(const std::vector<Line> &lines, size_t lineNo,
                        double radius, const Vector2 &optVelocity,
                        bool directionOpt, Vector2 &result);

    /**
     * \relates    Agent
     * \brief      Solves a two-dimensional linear program subject to linear
     *             constraints defined by lines and a circular constraint.
     * \param      lines         Lines defining the linear constraints.
     * \param      radius        The radius of the circular constraint.
     * \param      optVelocity   The optimization velocity.
     * \param      directionOpt  True if the direction should be optimized.
     * \param      result        A reference to the result of the linear program.
     * \return     The number of the line it fails on, and the number of lines if successful.
     */
    size_t linearProgram2(const std::vector<Line> &lines, double radius,
                          const Vector2 &optVelocity, bool directionOpt,
                          Vector2 &result);

    /**
     * \relates    Agent
     * \brief      Solves a two-dimensional linear program subject to linear
     *             constraints defined by lines and a circular constraint.
     * \param      lines         Lines defining the linear constraints.
     * \param      numObstLines  Count of obstacle lines.
     * \param      beginLine     The line on which the 2-d linear program failed.
     * \param      radius        The radius of the circular constraint.
     * \param      result        A reference to the result of the linear program.
     */
    void linearProgram3(const std::vector<Line> &lines, size_t numObstLines, size_t beginLine,
                        double radius, Vector2 &result);
}

#endif /* RVO_AGENT_H_ */
